package com.WFinstitute.util;
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.util.Random;

import javax.imageio.ImageIO;
import javax.imageio.stream.ImageOutputStream;

public class RandomCodeUtil {

    private ByteArrayInputStream image;//图像
    private String str;//验证码
    
    private RandomCodeUtil(){
        init();
    }
    
    public static RandomCodeUtil instance(){
        return new RandomCodeUtil();
    }

    public ByteArrayInputStream getImage() {
        return image;
    }

    public String getStr() {
        return str;
    }
    
    private void init(){
        //      在内存中创建图象  
        int width=85, height=20;  
        BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);

        //      获取图形上下文  
        Graphics g = image.getGraphics();  
        //      生成随机类  
        Random random = new Random();  
        //       设定背景色  
      //  g.setColor(getRandColor(200,250));  
        g.setColor(new Color(188,183,183));  
        g.fillRect(0, 0, width, height);  
        //      设定字体  
        g.setFont(new Font(Font.SERIF,Font.ITALIC,15));  

        
        //      随机产生300条干扰线，使图象中的认证码不易被其它程序探测到  
/*        g.setColor(getRandColor(160,200));  
        for (int i=0;i<300;i++){  
            int x = random.nextInt(width);  
            int y = random.nextInt(height);  
            int xl = random.nextInt(12);  
            int yl = random.nextInt(12);  
            g.drawLine(x,y,x+xl,y+yl);  
        } */ 
        //       取随机产生的认证码(6位数字)  
        String sRand="";  
        for (int i=0;i<6;i++){  
            //String rand=String.valueOf(random.nextInt(10));
            String rand = getRandomChar();
            sRand = sRand.concat(rand);  
            // 将认证码显示到图象中  
            g.setColor(new Color(20+random.nextInt(100),20+random.nextInt(10),20+random.nextInt(200)));  
          //  g.setColor(new Color(0,0,0));  
            //      调用函数出来的颜色相同，可能是因为种子太接近，所以只能直接生成  
            g.drawString(rand,13*i+6,16);    
        }  
        this.str=sRand;
        //       图象生效  
        g.dispose();  
        ByteArrayInputStream input=null;  
        ByteArrayOutputStream output = new ByteArrayOutputStream();  
        try{  
            ImageOutputStream imageOut = ImageIO.createImageOutputStream(output);  
            ImageIO.write(image, "JPEG", imageOut);  
            imageOut.close();  
            input = new ByteArrayInputStream(output.toByteArray());  
        }catch(Exception e){  
        System.out.println("验证码图片产生出现错误："+e.toString());  

        }
        this.image=input;
    }
    
      
    private Color getRandColor(int fc,int bc){  
        Random random = new Random();  
        if(fc>255) fc=255;  
        if(bc>255) bc=255;  
        int r=fc+random.nextInt(bc-fc);  
        int g=fc+random.nextInt(bc-fc);  
        int b=fc+random.nextInt(bc-fc);  
        return new Color(r,g,b);  
    }  

    
    public static String getRandomChar() {
          int index = (int) Math.round(Math.random() * 2);
          String randChar = "";
/*          switch (index) {
          case 0://大写字符
           randChar = String.valueOf((char)Math.round(Math.random() * 25 + 65));
           break;
          case 1://小写字符
           randChar = String.valueOf((char)Math.round(Math.random() * 25 + 97));
           break;
          default://数字
*/           randChar = String.valueOf(Math.round(Math.random() * 9));
/*           break;
          }*/
          return randChar;
         }
    
}